For Coaxial Cables

Coaxial cable (English abbreviation coax) is a type of cable used in radio frequency. The cross-sectional area of ​​this cable consists of four items, one within each other. The innermost is the live line, the line carrying the signal. This tip is surrounded by an insulator with a high dielectric constant. Around the insulator is a braid (or thin foil) of conductors. This braid is grounded. There is a protective cover on the outermost part. It is very important that the braid of the cable is grounded. Because in this way, the cable can pass near the devices that create electromagnetic fields without being affected. On the other hand, this structure enables coaxial cables to be more elastic than other cables of their own thickness. The current carried by the coaxial cable is a very high frequency current such as VHF or UHF. The direction of the current changes millions of times per second. (VHF is the frequency domain from 30 million to 300 million Hz, and UHF from 300 million to 3 billion Hz.)